The thecal compartment of antral follicles has been shown by Northern analyses to express the a2 and a3 chains of type IV collagen and the laminin (31 and 71 chains, and our observations of the a1 and a2 chains of type IV collagen (current study) and laminin 71 in the ‘thecal matrix’ suggest that cells in the thecal layer are capable of producing basal lamina components. However, the thecal expression of these molecules is not necessarily a contribution to the follicular basal lamina. This was particularly demonstrated for the laminin (31 chain, which was immunolocalized to the thecal vasculature but undetectable in the follicular basal lamina at most stages of follicular development. Nevertheless, it remains possible that in vivo, the follicular basal lamina receives a contribution from both the granulosa cells and the stroma or thecal cells. buy cheap antibiotics
Type IV collagen has been reported to be found in basal laminae. However, in the current immunolocalization study, relatively large amounts of a1(IV) and a2(IV) were found within the extracellular regions of the theca interna of antral follicles. These large diffuse areas of staining were not associated with the follicular basal lamina or the subendoth-elial or smooth muscle basal laminae of the vasculature.